1. Field of the Invention
The present invention relates to plate-like-object manufacturing methods, plate-like objects, gas-turbine combustors, and gas turbines.
This application is based on Japanese Patent Application No. 2009-110510, the content of which is incorporated herein by reference.
2. Description of Related Art
Plate-like objects having channels, through which a cooling medium flows, formed between both surfaces thereof are used as components for areas exposed to high-temperature environments in gas-turbine combustors, jet engines, space-related devices and the like. Because plate-like objects are cooled by causing the cooling medium to flow through the channels, plate-like objects can be used in the aforementioned areas that are exposed to high-temperature environments.
For example, because combustion cylinders in gas-turbine combustors are used in a high-temperature environment of about 1500° C., combustion cylinders are formed by using the aforementioned plate-like objects having a cooling function (for example, see the Publication of Japanese Patent No. 3192690).
Specifically, a single cylindrical combustion cylinder is formed by joining and assembling together a plurality of (e.g., four) plate-like objects. A known joining method, such as laser welding, is used for joining together neighboring plate-like objects (for example, see the Publication of Japanese Patent No. 3831638).
However, when joining the neighboring plate-like objects together in the above-described manner, if channels through which a cooling medium flows are open at the joint surfaces, the openings may get blocked as a result of welding, making it impossible for the cooling medium to flow through those channels.
The occurrence of such channels without the cooling medium flowing therethrough is a problem in that the cooling performance may vary among the plate-like objects and that the cooling performance may become degraded.
In light of this, a technology for causing the cooling medium to flow through the aforementioned channels by welding together the neighboring plate-like objects, forming grooves along the welded sections by partially cutting the welded sections, and connecting the blocked openings and the grooves is proposed.
Note that the aforementioned grooves are closed by covering them with a cover.
However, in the method of forming the grooves and closing them with a cover, as described above, it is necessary to provide the grooves by machining, such as grinding, after performing welding using a laser or the like, which is a problem in that dust is produced during the machining process, leading to deterioration of the working environment.
In addition, cracks may sometimes form when the welded sections and the grooves interfere with each other, and in that case, it is necessary to check whether or not there is a crack by performing inspection, such as X-ray imaging, after the welding process. If a crack is found, it is necessary to perform many readjustments, such as mending the crack, resulting in a problem in that the period required for manufacturing a turbine combustor is extended.
On the other hand, since the shape of the grooves varies depending on individual turbine combustors, the cover that covers the grooves needs to be fabricated in accordance with the actual shape of the grooves, resulting in a problem in that the period required for manufacturing a turbine combustor is extended.